1. Field of the Invention
The invention relates to an ignition timing control device and an ignition timing control method for an internal combustion engine.
2. Description of Related Art
In the internal combustion engines, knocking is more likely to occur as the temperature in the combustion chamber increases or as the octane number of the fuel decreases. Therefore, in a device described in Japanese Patent Application Publication No. 06-323224 (JP 06-323224 A), occurrence of knocking is suitably suppressed by retarding the ignition timing according to the octane number of the fuel and the intake air temperature, which is a parameter that correlates with the temperature inside the combustion chamber.
The related-art devices are configured to correct the ignition timing to retard when the intake air temperature is high. That is, the ignition timing is corrected when the intake air temperature is high. Retarding the ignition timing is likely to result in reduced engine output while being able to suppress occurrence of knocking. As a result, for example, fuel economy and drivability are likely to deteriorate.